A 0.18- $\mu$ m CMOS Dual-Band Frequency Synthesizer With Spur Reduction Calibration

This letter presents a 0.18 μm CMOS dual-band frequency synthesizer with charge-pump current mismatch calibration to reduce reference spurs. To enhance calibration accuracy the high-resolution phase detector (HRPD) is incorporated in this work. The measured output spur level is less than -63 dBc after the calibration circuits are activated and the reference spur reduction is more than 5.6 dB throughout the whole frequency range. The frequency synthesizer draws 16 mA from a 1.8 V power supply, and the covered frequency bands are 5.18-5.32 GHz and 5.74-5.82 GHz.